Manual strapping tool



Nov. 19, 1968 R, F. PLATTNER 3,411,551

MANUAL STRAP? I NG TOOL Filed March 17, 1965 v I 6 Sheds-Sheet 1 gawrz 3651172 1968 R. F. PLATTNER 3,411,551

MANUAL STRAPPING TOOL Filed March 17, 1965 6 Sheets-Sheet 2 Nov. 19,1968 R. F PLATTNER MANUAL STRAPPING TOOL 6 Sheets-Sheet 5 Filed March17, 196

[re vevzZor fiOcrfFPZZW? effigy Nov. 19, 1968 R. F. PLATTNER MANUALSTRAPP ING IfOOL 6 Sheets-Sheet 4 Filed March 17/1965 jzauerziawfi9erZFhZZrzen Wt Q. Q w; @75 2 Nov. 19, 1968 R. F. PLATTNER MANUALSTRAPPING TOOL l-\-l-).\- Ii 1 i; 7 P. m

m NN ww Ssw ni m 4 Mam R. Q3 6 5 m r Rm Rum Nw NW N ms Q vllu (dz/.4

Filed March 17, 1965 Nov. 19, 1968 R. F. PLATTNER 3,411,551

MANUAL STRAPPING TOOL Filed March 17, 1965 6 Sheets-Sheet 6 UnitedStates Patent 3,411,551 MANUAL STRAPPING TOOL Robert F. Plattner,Chicago Heights, 11]., assignor to Interlake Steel Corporation, Chicago,111., a corporation of New York Filed Mar. 17, 1965, Ser. No. 440,462 18Claims. (Cl. 140--93.4)

ABSTRACT OF THE DISCLOSURE A strapping tool for tensioning overlappingends of a strap loop'encircling an object having mechanism permittingsingle handle operation of both strap tensioning and joint formingmechanisms thereon.

This invention relates to a manual strapping tool of the type employedfor crimping a seal about overlapping ends of a strap loop and moreparticularly is concerned with a manual strapping tool that is ofsimplified construction and that is easy to operate through a fulloperating sequence.

Some of the principal steps in the operating sequence which requiremanual manipulation of the tool are: positioning the tool in engagingrelation upon the overlap ping strap ends after a strap has been loopedabout a package or other object that is to be tied; tensioning the straploop by repeatedly ratcheting a rotary gripper wheel; applying andcrimping a seal about the overlapping strap ends after tensioning iscompleted; feeding another seal for use in the next joint sealingapplication; and releasing the tool after the first seal is completed.

In the prior art, tools for accomplishing this sequence have involvedexcessive complexity that encumbered both the construction and theoperation, and the present invention has for its principal object theprovision of a tool for manual operation through such a sequence withoutneed for extraneous control mechanism.

Another object is the provision of a tool for manual operation throughsuch a sequence wherein a single actuating arm sequentially controlsactuation of the mechanisms that perform the various functions of acomplete strapping cycle.

A further object of the invention is the provision of a manuallyoperated tool arranged to enable a single actuating arm to be movedthrough a full operating sequencel of a complete strapping cycle whilerequiring only oriehand of the operator, with the other hand of theopiia'tor being free to assist in orienting the package or in orientingthe strap loop or in performing similar functions incident to astrapping-operation.

It is an important object of the invention to provide an improvedmechanism in combination with a manually operated strapping tool of atype having a driving pawl carried on and swingable with an auxiliaryframe under the control of an actuating arm for ratcheting a rotarytensioning wheel device in a strap tensioning direction, with theimproved mechanism including a pawl control element mounted in theauxiliary frame and automatically shiftable to disengage the drive pawlat the end of the seal forming action and with the pawl thereafter beingautomatically resettable as the actuating arm is swung to a position.for releasing the tool from the previously sealed strap ends.

Still another object of the invention is the provision of a manuallyoperated strapping tool incorporating a rotary adjustable drive pawlequipped with an externally accessible release pin to enabledisengagement of the drive pawl by direct manual manipulation wheneverrequired.

In tools of the type herein referred to, tensioning of the strap loop bymeans of a rotary tensioning wheel is accomplished in certain cases byemploying a plug adjustably mounted within the frame portion over whichthe strap passes as it is tensioned. The overlapping strap ends passbetween the plug and the rotary tensioning wheel. Both the plug and thewheel have sharp teeth which bite into the strap. The teeth on the plugretain the lower strap end and keep it anchored in a fixed locationwhile the teeth on the wheel cause the upper strap end to be movedacross the lower strap end to merely tension the strap loop. On many ofthese tools it is possible to adjust the plug too close to the tensionposition of the wheel with the result that rotation of the wheel withoutthe strap in position between the wheel and plug will cause breakage ofthe plug or wheel teeth requiring replacement of the parts. It isanother object of this in vention to provide an improved constructionalrelationship -for the positioning of an adjustable plug and thetensioning wheel whereby a satisfactory distance is automaticallymaintained between the two parts regardless of the position to which theplug is adjusted.

Other objects and advantages of the present invention will be apparentfrom the following description and claims, and are illustrated in theaccompanying drawings which show structure embodying preferred featuresof the present invention and the principles thereof, and what is nowconsidered to be the best mode in which to apply these principles.

In the accompanying drawings forming a part of this specification and inwhich like numerals are employed to designate like parts throughout thesame:

FIG. 1 is a side elevational view of a strapping tool constructed inaccordance with this invention, with its parts shown in positionsassumed when the tool grips both the leading .and supply ends of a strapand has tensioned the supply end of the strap;

FIG. 2 is a corresponding side elevational view of the tool with itsparts in positions they assume at the beginging of a joint sealingoperation (full lines), and with the handle being shown in phantom linesat the position it assumes when a joint is completed;

FIG. 3. is an elevational view of the side of the tool opposite of thatof FIGS. 1 and 2 and showing its parts in positions assumed when thetool is ready for the reception of a strap;

FIG. 4 is a sectional view through the various parts of the tool and istaken as indicated on the line 44 of FIG. 2;

FIG. 5 is a fragmentary face view of the seal feeding mechanism and istaken as indicated by the line 55 of FIG. 1;

FIG. 6 is a fragmentary face view of the top of the seal head and istaken on the line -66 of FIG. 1;

FIG. 7 is a section on the line 7--7 of FIG. 1 to illustrate the jointsealing mechanism;

FIG. 8 is a section taken on the line 8-8 of FIG. 1 illustrating thedrive for the joint sealing mechanism;

FIG. 9 is a section taken on the line 9--9 of FIG. 2 illustrating thestrap aligning lever in operative position;

FIG. 10 is a section taken on the line 10-10 of FIG. 1 and illustratingthe strap tensioning mechanism;

FIG. 11 is a lengthwise section taken on the line 11l1 indicated on FIG.4;

FIG. 12 is a fragmentary section taken as indicated on the line 12-12 ofFIG. 11;

FIG. 13 is a transverse section taken on the line 1313 of FIG. 12 toillustrate the drive pawl in its engaged relation to the ratchet and toillustrate the pawl control elements in the positions they assume atthis stage.

FIG. 14 is a fragmentary section corresponding gencrs ally to that ofFIG. 12 and showing the pawl and pawl control parts in their disengagedposition;

FIG. 15 is a transverse section taken as indicated on the line 15-15 ofFIG. 14 and illustrating the pawl and pawl control elements in theirdisengaged positions;

FIG. 16 is an exploded perspective view of the drive pawl, the pawlrelease pin, and the detent pin better illustr-ating the action andcooperation of these parts; and

FIG. 17 is a fragmentary top plan view of the strap support portion asviewed along 1717 of FIG. 10.

GENERAL DESCRIPTION Referring now to the drawings and particularly toFIGS. 1, 2, 3 and 11 thereof, a preferred embodiment of the strappingtool of this invention is shown therein for the purposes of illustrativedisclosure as consisting of a main frame M which is to be engagedagainst the package being tied, a tensioning mechanism T mounted toswing upon the main frame M about an axis defined by a transverse pin20, an auxiliary frame F mounted to swing about a transverse pin 21 thatis incorporated in the tensioning mechanism T, a seal head assembly Hcarried on the auxiliary frame F and including seal forming mechanism22, a seal magazine 23 and seal feeding mechanism 24, and finally, anactuating arm A carried on the seal head H for swinging the seal head Hand auxiliary frame F as a unit about the pin 21, with the actuating armA being rotatable relative to the auxiliary frame F (from full line tophantom line positions shown in FIG. 2) for actuating the variousmechanisms 22, 23, and 24 carried in the seal head H. The tensioningmechanism T includes a gripper wheel unit (see FIGS. 4, 10, and 11) fortensioning the straps S and comprised of mating gripper discs 25 thatflank and are locked to a ratchet wheel 26 by lock pins 25F, all torotate in unison about the pin 21.

The invention contemplates the provision of a strapping tool capable ofbeing handled and operated by one hand and the general arrangement andoperation of the device will be apparent to those familiar with combinedstrap tensioning and sealing tools. The normal position of the toolparts is as illustrated in FIG. 1. The operator may grip the main frameM and actuating arm A in one hand and squeeze to move the parts towardsthe position illustrated in FIG. 3 to open the device sufficiently toengage upon the overlapping ends of a strap S (FIG. 1) which has beenpositioned around the package which is to be tied. Relaxation of thegrip restores the parts to the position of FIG. 1, but the strap endsare now engaged in retained aligned position within the tool.

The actuating arm A may now be moved counterclockwise as far as theposition illustrated in full lines in FIG. 2 and then may be repeatedlycranked towards the position illustrated in FIG. 1 to apply tension tothe supply end of the strap while the free end of the strap is heldstationary by the tool, thereby tightening the strap about the packageto the desired extent. During this strap tensioning action, theactuating arm A and auxiliary frame F move as a unit pivoting about thetransverse pin 21. Thereafter, the parts are brought to the positionillustrated in full lines in FIG. 2 and the actuating arm A is thenpivoted counterclockwise to the phantom line position illustrated inFIG. 2. During this counterclockwise movement of the actuating arm, apreviously fed seal is crimped about the overlapping ends of the strapby the seal forming mechanism 22 and the seal feeding mechanism 24 iscocked to supply another seal from the seal magazine 23 for the nextstrapping operation.

During the strap tensioning cycle, a drive pawl 27 (see FIGS. 4, 11, and12) carried on the auxiliary frame F, actuates the ratchet wheel 26while a holding pawl 28 mounted on the pin 20 prevents return of theratchet wheel, thereby to maintain the set tension on the strap. Duringthe final stages of the operation of the seal forming mechanism 22, thedrive pawl 27 is partly rotated counterclockwise as viewed in FIG. 11 tobecome disengaged from the ratchet wheel as will be describedhereinafter. Subsequent clockwise movement of the actuating arm A fromthe phantom line position of FIG. 2 towards the full line position ofFIG. 2 will not further tension the now sealed strap because the drivepawl 27 is disengaged, but such movement enables the seal feedingmechanism 24 to complete the supply of a freshly released seal to theseal actuating mechanism 22 where it is retained until the next packageis tied with a strap and the strap tensioned by the tool.

Upon further clockwise movement of the actuating arm A from the fullline position of FIG. 2, to and through the position of FIG. 1, theholding pawl 28 is disengaged from the ratchet 26 by the action of aroller 28R journailed on a pin 28F that is carried on auxiliary frame Fand thereafter the drive pawl 27 is reset upon engage ment with anabutment cam 29 (see FIGS. 2 and 11) provided on the main frame M toreversely rotate the pawl 27 to a ratchet engaging position. The tool isnow ready for the next sealing operation. All of these operations areconveniently performed with a single hand as is made possible by theteachings of the present invention.

SPECIFIC D'ECRIPTION The detailed construction of the parts of the toolmay now be described. The main frame M has a generally flat elongatedbase portion 30 presenting an underface for contact with a package thatis to be tied. The base 30 merges with an upstanding wall 31 (FIGS. 3and 10) medially along one side and merges with a lengthwise handle 32that extends above the right end of the base as viewed in FIGS. 1 and 2.The region where the handle 32 and the side wall 31 merges is enlargedtransversely as indicated at 32T in FIG. 11 and terminates in anoverhanging side wall 33 that is spaced from the main side wall 31 (seeFIG. 10) to define an open center region for mounting of the tensionmechanism T.

The-base 30 is provided at its front end with a strap guide 34 securedby screws 35 (see FIGS. 1 and 9). The strap guide 34 is provided with anoverhanging lip 34L to engage the inner edge of the strap ends andmaintain the strap against separation prior to application of the seal.The base 30 is also fitted with an insert in the form of a knurled plug36 (see FIGS. 1 and 2) located beneath the gripper discs 25 to engageand hold stationary the leading strap end which is at the bottom,whereas the gripper discs 25 engage and tension the movable supply endof the strap which is uppermost.

The tensioning mechanism T is mounted in the region between the sidewalls 31 and 33 of the main frame M and it includes a cradle 37 that isgenerally of U-shape to define a pair of depending arms 37A (see FIG.10). The cradle 37 is journalled on the crosspin 20 that is carriedinupper regions of the side walls 31 and 33 of the main frame M toprovide a swingable mounting for the tensioning mechanism T. Adjacenttheir lower ends, the cradle arms 37A are fitted with ring bearings 38(see FIG. 4) for rotatably mounting the crosspin 21 on which the gripperdiscs 25 and ratchet wheel 26 are journalled. The holding pawl 28 formaintaining the gripper discs 25 and ratchet wheel 26 against returnmovement is journalled centrally on the crosspin 20. The holding pawl 28is resiliently biased to its illustrated position of FIG. 11 by means ofhelical springs 40 (see FIGS. 4 and 10). The engagement of the ratchet26 for the rotation of the gripping discs 25 in a strap tensioningdirection is effected through the pulling pawl 27 under the control of apawl release pin 41 (see FIGS. 4 and 11). These parts are carried in theauxiliary frame F and their function is described hereinafter.

The outboard cradle arm 37A has a downward extension 37F as is apparentin FIGS. 1, 2, and 11 to serve as a foot that rests against the knurledplug 36 when the tool is not in use.

The particular construction shown of the knurled plug 36 offers aspecial advantage over prior devices. The plug 36 is circular incross-section and has its sharp upstanding teeth 36A located at asmaller diameter circular portion centrally within the full circularshape.

Surrounding the teeth 36A is a flat annular portion 36B which is at aradial distance in alignment with the path of movement of the downwardextension 37F so that this extension 37F rests directly on the annularportion 36B when the cradle 37 is in its biased position as urged by thespring 42, for example, as shown in FIG. 1. One of the shortcomings ofprior devices employing adjustable toothed plugs is that they can beelevated too much so that the sharpened teeth of the gripper discs arein contact and interference with the teeth of the plug. Unintentionalrotation of the discs when no strap is present between the discs and theplug will then cause breakage of teeth either on the plug or the discs.There is nothing on those devices to limit the adjustment. By thestructure shown, any adjustment upward of the plug 36 causes the annularportion 36B to also be elevated because it is an integral part of theplug 36. This, in turn, elevates the contact level of the extension 37Fwith the plug 36 so that contact between the teeth 25A on the gripperdiscs 25 and the teeth 36A on the plug 36: is always prevented with theresult that accidental breakage of the teeth on the discs 25 or plug 36is prevented in the situation when no strap is between the discs 25 andthe plug 36 and the operator causes the discs to be rotated.

The rear cross wall of the cradle 37 is provided cen trally with arearward lug 37L to which is anchored one end of an extension typecradle return spring 42 which is nested in a through bore provided inthe main frame at the region of the front of the handle 32. The cradlereturn spring 42 normally urges the cradle 37 and the gripper discs 25in a counterclockwise direction to load them against the upper strapend. The continuously acting force applied through the cradle 37 and itsarms 37A by means of the cradle return spring 42 prevents undesiredslippage of the strap. This force is, of course, greatly augmented whenthe actuating arm A acts to drive the gripper discs 25 through theratchet system.

Finally, a band guide 37B, as shown in FIGS. and 11, is mounted upon thepin to extend alongside and beyond the outboard cradle arm 37A andterminate in a guide portion 376 that projects into a notch N providedin the base portion 30.

The auxiliary frame F and seal head assembly H are built upon a hollowmain body casting 70 having a cylindrically bored generally rectangularupper end 71 and outwardly flaring depending side walls 72, as is bestseen in FIG. 7. Fore and aft spaced cross walls 43 and 44 span the lowerportions of the side walls 72, a full height filler plate 73 overliesthe front cross wall 43 and the upper end 71 of the main body 70, andfinally, a seal housing casting 74 has a lower rear wall 75 overlyingthe filler-plate 73, with a set of bolts 45 securing the cross walls 43and 44, the filler plate 73, and the seal housing 74 in fixed relationupon the side walls 72 of the main body. The rearmost crossplate 44 hasa pair of rearwardly projecting side arms 44A pivoted on the crosspin 21that mounts the ratchet and gripper wheel assembly. The pin 21 is heldin place in the side arms 44A of the auxiliary frame F by the bolt 46and nut 47 and washers 48 all as shown in FIG. 4.

The joint sealing mechanism 22 is mounted within the chamber definedbetween the plates 43 and 44 of the auxiliary frame and it may be of anyconventional construction known to those skilled in this art. Forpurposes of disclosure it is shown herein as including a center pair ofcooperating sealing jaws 50' which are rotatable about the axes of pivotpins 51. As is conventional, the sealing jaws 50 are flanked by sidepairs of sealing jaws 52 which also are rotatable about the axes of thepivot pins 51.

These sealing jaws 50 and 52 are seen in FIGS. 1, 4 and 11. As isconventional, the center pair of sealing jaws 50 are spaced from eachside pair of sealing jaws by a pair of platelike punches 53 which arearranged to engage against the upper face of the seal while it is beingdeformed by closure of the jaws. These punches 53 together with thesealing jaws are all interenga-ged in side by side stacked relation by apair of punch return pins 54.

A vertically slidable crosshead 55 operates in the upper end 71 of themain body 70 and (is connected to drive a crosshead pin 56. Thecrosshead pin 56 is journalled in the upper ends of two links 57 and 58.The link 57 is of a single thickness and is provided with two rollers 59on a pin 60 at its lower end, the rollers 59 being mounted on oppositesides of the link 57. The link 58 is forked to provide two ears at itsupper end with the upper end of the link 57 positioned between the twoears at the upper end of the link 58. The lower end of the link 58 isprovided with two rollers 61 (FIG. 7) mounted on a pin 62, these rollers61 being positioned on opposite sides of this link. (Only one of therollers 61 is visible in the drawings.)

The four rollers 59 and 61 are used to bear against the upper surfaces53U of the vertically movable punches 53 to cause their downwardmovement. The downward movement is caused as the rollers 59 and 61 aremoved laterally away from each other and ride up the sloped portions ofthe upper surfaces 53U of the punches 53.

The movable punches 53 are provided with two closed slotted openings 538(FIG. 7) which are guided on the pins 51 which confine them laterallyduring their vertical movement. These pins 51 project in fixed relationinto openings in the crossplates 43 and 44 so they may also serve aspivot pins for the jaws 50 and 52. These jaws and punches, therefore,are stacked in sandwiched relationship, as is shown in FIG. 11. On eachpin 51 is a jaw 52, a punch 53, a jaw 50, a punch 53 and another jaw 52.The three jaws pivoted on each pin 51 are connected together by means ofa pin 54 so that all three jaws pivot as a single integral unit on thepin 51. Although there are no further connections on the middle jaws 50,the upper ends 52U of the flanking jaws 52 extend upwardly to where theyare pivoted on the pins 60 and 62 which are the same pins that supportthe four rollers 59 and 61. The pins 54, in addition to connecting thejaws together, cause upward vertical movement of the punches 53 on thereturn stnoke of the crosshead 55 as the pins 54 react against surfaces53L.

With this linkage arrangement, when'the crosshead 55 moves downward,this causes, in turn, downward movement of the punches 53 and pivotalmovement of the jaws 50 and 52. As this occurs, the lower central edgesof the punches 53 react against the upper surface of the seal 63 (FIG.7). Also; during this downward movement of the crosshead 55, the jaws 50and 52 pivot to move their tips closer together and push the seal legsbeneath the two overlapping strap ends which are at this time inalignment through the seal 63. Upon further movement, tne jaw tips reactagainst the bottom portions of the overlapping straps while pressingagainst the seal legs to serve as the reaction forces opposing thedownward force exerted by the lower central edges of the punches 53.This action causes intermediate tab portions of the seal to be severedand bent downwardly to form the conventional interlocking type jointwhich is Well known in this art. Further details of the jaw action andjoint are given in Hall et al. Patent No. 3,032,075 granted May 1, 1962.

During the final formation of the joint, a shear blade 64 (see FIGS. 4and 11) is driven down by the crosshead pin 56 to score the supply endof the strap as the joint is being held in the joint sealing mechanism22. Thereafter, when the joint is completed and the tool is removed fromthe vicinity of the joint, the supply end of the strap is bent andflexed at the score line produced by the shear blade 64 until it breaksat the weakened score line. The shear blade 64 is nested in a centralvertical recess provided in the front crossplate 43 and the shear bladehas a vertical slot 648 adjacent its upper end to receive the front endof the crosshead pin 56 in .a lost motion relation. The shear blade 64is retracted when the crosshead 55 elevates the crosshead pin 56following the joint forming action. The lost motion afforded by the slot645 enables the jaws 50 and 52 to be substantially fully operated intheir joint forming stroke prior to the operation of the shear blade 64.

The seal housing casting 74 defines a generally rectangular seal storagemagazine that is open at the top and bottom and along one side. A pairof shelf brackets 65 are disposed in side by side relation beneath themagazine and have inwardly extending lips 65L defining a band guidewayand arranged to receive and temporarily retain each seal as it isdischarged from the magazine. Thus, the lowermost seal 63 rests with itslegs positioned upon the lips 65L as is best seen in inverted relationat the top of FIG. 5. A follower type plunger 66 is disposed to ridevertically in the magazine and rest upon the uppermost seal of thestack. A helical band spring 67 is coiled about a pin 66 'P within apocket provided in the follower 66 and the exposed end of the band 67extends along the open side face of the magazine and anchors within thebase 74B of the seal housing casting so that the band spring 67 normallydraws the follower downwardly to effect a continuously acting positiveseal feed.

Seals may be loaded in stacked relation through the open top of the sealmagazine and the stacked seals 63 are apparent in any of FIGS. 1, 2, and11. In order to I add new seals to the seal housing 74, the follower 66is removed from the open top end of the magazine by pulling it upwardagainst the force of the band spring 67 which unwinds sufiiciently topermit such travel. After the seals are added, the plunger 66 isreplaced in the magazine.

Immediately below the bottom seal of the stack there is provided a sealfeed finger 68 (see FIG. 11) that is reciprocable lengthwise in thegroove defined by the shelf brackets 65. The free end of this finger 68is provided with a V-shaped groove for engaging the seal endwise inposition for feeding the seal from the stack to the jaws 50 and 52. Theouter captive end of the seal feed finger 68 terminates in a U-shapedportion 68U (see FIG. the arms of which are pivoted on a pin 69 that iscarried at the lower end of the bell crank shaped seal feed element 24.

The seal feed element 24 has a front arm 77 and a laterally offset sidearm 78. At the region of the juncture of the arms 77 and 78, the upperend of the front arm 77 is shaped to flank a pair of lugs 74L integrallycarried on the seal housing casting 74 and mounting a pivot pin 79 bywhich the seal feed element 24 is pivoted to the housing 74. A coilSpring 80 encircles the pin 69 and at its ends reacts between the bellcrank arm 77 and the seal feed finger 68 to cause the finger to bebiased rotationally in a lifting relation against the seal stack. A coilspring 81 encircles the pin 79 and its ends react between the bell cranklever 77 and the seal housing 74 normally to bias the the bell crankrotationally in a counterclockwise sense as viewed in FIGS. 1, 2, and11. The free end of the side arm 78 of the bell crank is forked andprovided with a pivot pin 82 that mounts a cam roller 83 as is best seenin FIGS. 3, 5 and 6.

The actuating arm A is also forked to present laterally spaced mountingears 84 which are pivotally mounted at opposite sides of the main bodycasting 70 (see FIG. 8). A one-piece shaft 85 is disposed crosswisewithin the top of the body casting 70 and has an integral pinion gear85F formed at its central region and flanked by stub shaft portions 858.Bushings 86 are press fit in opposite sides of the body casting 70 andcarry needle bearings 87 to provide an anti-friction mounting for thestub shaft portions 858 which are extended outwardly of the body withthe left hand stub portion directly serving as a pivot pin for the leftear of the actuating arm and with the right hand stub portion beingknurled or otherwise non-circular at its outer end 85B and engaged in amating socket provided in an approximately centrally located stub sleeveportion 88S of an outboard cam 88. The stub sleeve 88S presents acircular periphery that serves as a mounting pin for the right hand ear84 of the actuating arm.

The cam 88 has a mounting arm 88A anchored fast to the actuating arm Aby means of a bolt 89 and has a contoured cam sector 88C extendingtowards the side arm 78 of the bell crank and engageable with its roller83 to effect pivoting action of the bell crank and withdrawal of theseat teed finger 68 in a predetermined timed relation to the pivotingmovement of the actuating arm as it travels from the full line positionof FIG. 2, towards the dotted line position of FIG. 2. As statedhereinbefore, it is during this portion of the travel of the actuatingarm A that it undergoes relative swinging movement with respect to themain body casting 70. The pinion teeth 85P on the shaft 85 rotate withthis movement of the actuating arm to drive the crosshead which isprovided with rack teeth 5ST along its upper portion in meshing relationto the pinion teeth P.

It may be noted that the action of the cam 88 in cocking the bell crankoccurs concurrently with the action of the pinion 85P in driving thecrosshead 55 downwardly for operating the jaws 50 and 52 and the punches53 and also for operating the shear blade 64 for scoring the supply endof the strap. At the time that the seal feed finger is cockedsufficiently to engage the lowermost seal of the stack for imparting anend=wise feed motion, a projection 34A on the strap guide 34 serves asan abutment preventing completion of the seal feed cycle until theactuating arm A is reversely swung from the dotted line position of FIG.2 partway towards the full line position of FIG. 2 to clear the arcuateregion of the cam sector 88C sufiiciently to enable the spring 81 of thebell crank to effect return movement of the bell crank and correspondingseal feeding movement of the finger 68.

One-hand operation Mechanism is provided in the rear crossplate 44 tocontrol the timing of the engagement and disengagement of the drive pawl27 and the rachet 26 in accordance with the particular phase of swingingmovement of the actuating arm A. The drive pawl 27 is in the form of aone piece cylindrical pin having arcuate cutouts 27A (FIG. 16)intermediately along it and flanking a set of integral drive teeth 27Tthat mesh with the ratchet teeth for causing rotation of the ratchetwhen the auxiliary frame F swings from the full line position of FIGS.2. and 11 to the full line position of FIG. 1 as it is being repeatedlycranked during the strap tensioning cycle. During this strap tensioningcycle, the rotational position of the drive pawl 27 with respect tocrossplate 44 is illustrated in FIGSv 11 and 13.

The drive pawl 27 has a lengthwise groove 27G along the region that isopposed to the pawl teeth 27T and at one end the pawl has a manualrelease pin 90 (FIGS. 1 and 2) projecting radially for use indisengaging the pawl where, for one reason or another, tension must berelieved on the strap prior to completing the full strapping cycle. Thepawl at its other end has a sector shaped endwise projecting cam 270which is engageable with the abutment 29 on the side wall 31 of the mainframe to reset the pawl from disengaged relation to engaged relationwith respect to the ratchet teeth after the sealing cycle has beencompleted and during the time that the actuating arm is moving towardsthe full line positions illustrated in FIGS. 1 and 3. The crossplate 44has a vertical central bore 44V in which a pawl release pin 91 isshiftable. The pawl release pin 91 has a generally cylindrical lower end91C, a relieved intermediate portion 911 of semi-circular form andprovided with an integral lug 92 and a further relieved upper end 91Uwhich underlies an outwardly projecting end 56E on the crosshead pin.

The integral lug 92 of the pawl release pin is engageable in the groove27G of the driving pawl to effect rotation of the driving pawl 27 inaccordance with the vertical position of the pawl release pin 91. Whenthe pawl release pin 91 is elevated (see FIG. 13), it holds the drivingpawl 27 engaged with the ratchet 26, and when the pawl release pin 91 isdepressed (see FIG. 15), the driving pawl 27 is disengaged from theratchet 26. The crossplate 44 is provided with a side bore 448intersecting its vertical bore 44V and accommodating a detent pin 93 andload spring 94 normally to bias the detent pin towards and against thepawl release pin 91. The adjacent side face of the pawl release pin hasa conical detent 91D normally receiving the tapered nose of the detentpin 93 so that the detent pin exerts a vertical lifting action holdingthe pawl release pin 91 elevated and maintaining engagement of the drivepawl 27 with the ratchet 26 (see FIGS. 12 and 13). This relationshipobtains during the application of the tool to a band, during thetensioning cycle, and during most of the seal crimping cycle. However,during the final phase of the seal crimping cycle of the jaws andpunches, the crosshead pin 56' engages and forcibly depresses the pawlrelease pin, the detent pin 93 retracting against its load spring 94 toaccommodate this, so that the drive pawl 27 is rotated to a positionwhere its teeth 27T are out of engagement with the ratchet teeth (seeFIGS. 14 and 15). The detent pin 93 now bears against the side face ofthe pawl release pin 91 and cannot exert a lifting action and hencecannot re-establish engagement of the drive pawl 27.

The release of the drive pawl 27 at the end of the downward sealcrimping stroke of the actuating arm A and crosshead 55 enables returnmovement of the actuating arm A to the position of FIG. 1 withoutfurther tensioning the now-sealed strap. Further return movement of theactuating arm through and past the position of FIG. 1 concurrentlyreleases strap tension and resets the drive pawl 27, and when theposition of FIG. 3 is reached, the tool frees the strap and may beremoved from the package, it being immediately ready for application toanother package to tension and seal a strap about it.

Strap tension on the sealed loop of strap is released by the roller 28Rengaging the holding pawl 28 to release the same from the ratchet 26.Reset of the drive pawl 27 is concurrently accomplished by action of theside wall abutment 29 on the cam end 27C causing reverse rotation of thepawl 27 which, in turn, causes elevation of the pawl release pin 91 andenables the detent pin 93 to re-enter the detent 91D and again exert alifting action that maintains the drive pawl 27 engaged with the ratchet26.

It will be recalled that the drive pawl 27 normally engages the ratchet26 during initial application of the tool, during strap tensioning, andduring seal crimping until being disengaged as the actuating arm Acompletes its crosshead lowering stroke. The drive pawl 27 remainsdisengaged during return of the actuating arm A towards initial positionand is reset as the actuating arm completes its return movement. All ofthe related functions of the tool are also automatically responsive tothe actuating arm movement and all in a relationship to require only onehand operation Thus, when the tool is initially cocked to the FIG. 3position to enable it to engage a strap, one hand is able to grip thehandle 32 and actuating arm A simultaneously. Thereupon, the returnspring 42 acts to hold the tool engaged upon the strap and one hand issufiicient to crank the actuating arm through repeated strap tensioningmovement. If necessary, such tensioning movement may be interrupted andtension relieving by manually disengaging the drive pawl 27 by means ofthe conveniently located release pin 90 (FIGS. 1 and 2) followed byswinging the actuating arm A back to the FIG. 1 position.

Once the strap has been adequately tensioned, the actuating arm A isswung to its dotted line position of FIG.

10 2 to effect seal crimping, and thereafter it is swung towards itsrelease position, again only one hand being required. The fact that alloperating elements are controlled by the actuating arm includingparticularly the pawl operation on the ratchet enables this tool to beoperated with only one hand.

Thus, while preferred constructional features of the invention areembodied in the structure illustrated herein, it is to be understoodthat changes and variations may be made by those skilled in the artwithout departing from the spirit and scope of the appended claims.

What is claimed is:

1. In a strapping tool for tensioning and sealing the overlapping endsof a strap loop that encircles an object, a main frame, tensioning wheelmeans rotatable about an axis that is swingably carried by said mainframe, a sealer head swingable about said axis for movement to and fromsealing position, a drive pawl carried with said sealer head havingengagement with said tensioning wheel means during swinging movement ofsaid sealer head in a first rotary direction through a first arcuaterange of swinging movement, an actuating arm swingable conjointly withsaid sealer head for driving said wheel means by means of said drivepawl in said first rotary direction, said arm being pivotable relativeto said sealer head when the sealer head is at sealing position to movein an opposite rotary direction for operating said sealer head to crimpa seal about said overlapping ends, means responsive to operation of thesealer head for disengaging the drive pawl from the tensioning wheel toavoid further strap tensioning following crimping of the seal, and meansresponsive toswinging said actuating arm and sealer head through andbeyond said first arcuate range of swinging movement for resetting thedrive pawl to a position of engagement with said tensioning wheel.

2. In a strapping tool for tensioning and sealing the overlapping endsof a strap loop that encircles an object, a main frame, tensioning wheelmeans rotatable about an axis that is swingably carried by said mainframe, a sealer head swingable about said axis for movement to and fromsealing position, a drive pawl carried with said sealer head havingengagement with said tensioning wheel means during swinging movement ofsaid sealer head in a first rotary direction through a first arcuaterange of swinging movement, an actuating arm swingable conjointly withsaid sealer head for driving said wheel means by means of said drivepawl in said first rotary direction, said arm being pivotable relativeto said sealer head when the sealer head is at sealing position to movein an opposite rotary direction for operating said sealer head to crimpa seal about said overlapping ends, control means carried with saidsealer head and shiftable between first and second stable positions,said control means when in said first stable position acting to hold thedrive pawl in engagement with the tensioning wheel means and when insaid second stable position allowing the drive pawl to be free ofengagement with the tensioning wheel means, means responsive to pivotingmovement of said arm in said opposite rotary direction relative to saidsealer head to move said control means to said second position duringfinal operation of the seal forming mechanism, and means responsive tomovement of said actuating arm and said sealer head in said first rotarydirection through and beyond said first arcuate region for releasingstrap tension and for resetting said drive pawl to tensioning wheelengagement and returning said control means to said first position.

3. In a strapping tool for tensioning and sealing the overlapping endsof a strap loop that encircles an object, a main frame, tensioning wheelmeans rotatable about an axis that is swingably carried by said mainframe, an auxiliary frame swingable about said axis, a drive pawlcarried by said auxiliary frame and having engagement with saidtensioning wheel means during swinging movement of said auxiliary framein a first rotary direction through a first arcuate range of swingingmovement, a sealer head mounted on said auxiliary frame for movement toand from sealing position, an actuating arm swingable conjointly withsaid auxiliary frame and sealer head for driving said wheel means bymeans of said drive pawl in said first rotary direction, said arm beingpivotable relative to said auxiliary frame when the sealer head is atsealing position to move in an opposite rotary direction for operatingsaid sealer head to crimp a seal about said overlapping ends, meansresponsive to operation of the sealer head for disengaging the drivepawl from said tensioning wheel means to avoid further strap tensioningfollowing crimping of the seal, and means responsive to swinging saidactuating arm and sealer head through and beyond said first arcuaterange of swinging movement for resetting the drive pawl to a position ofengagement with said tensioning wheel means.

4. In a strapping tool for tensioning and sealing the overlapping endsof a strap loop that encircles an object, a main frame having meansproviding a fixed pivot axis and means mounting a floating axis parallelto and swingable about the pivot axis, tensioning wheel means rotatableabout the floating axis, an auxiliary frame swingable about saidfloating axis, a drive pawl carried by said auxiliary frame and havingratcheting engagement with said tensioning wheel means during swingingmovement of said auxiliary frame about the floating axis in a firstrotary direction through a first arcuate range of swinging movement, asealer head mounted on said auxiliary frame for movement to and fromsealing position, an actuating arm swingable conjointly with saidauxiliary frame and sealer head for ratcheting said wheel means by meansof said drive pawl in said first rotary direction to cause said wheelmeans to tension the strap loop, said arm being pivotable relative tosaid auxiliary frame when the sealer head is at sealing position to movein an opposite rotary direction for operating said sealer head to crimpa seal about said overlapping ends, means responsive to operation of thesealer head for disengaging the drive pawl to avoid further straptensioning following crimping of the seal, and means responsive toswinging said actuating arm and sealer head through and beyond saidfirst arcuate range of swinging movement for resetting the drive pawl toa position of ratcheting engagement.

5. In a strapping tool for tensioning and sealing the overlapping endsof a strap loop that encircles an object, a main frame having meansproviding a fixed pivot axis and means mounting a floating axis parallelto and swingable about the pivot axis, tensioning wheel means rotatableabout the floating axis, an auxiliary frame swingable about saidfloating axis, a drive pawl carried by said auxiliary frame and havingratcheting engagement with said tensioning wheel means during swingingmovement of said auxiliary frame about the floating axis in a firstrotary direction through a first arcuate range of swinging movement, asealer head mounted on said auxiliary frame for movement to and fromsealing position, an actuating arm swingable conjointly with saidauxiliary frame and sealer head for ratcheting said wheel means in saidfirst rotary direction, said arm being pivotable relative to saidauxiliary frame when the sealer head is at sealing position to move inan opposite rotary direction for operating said sealer head to crimp aseal about said overlapping ends, control means carried by saidauxiliary frame and shiftable between first and second stable positions,said control means when in said first stable position acting to hold thedrive pawl in ratcheting engagement with the tensioning wheel means andwhen in said second stable position allowing the drive pawl to be freeof ratcheting engagement with the tensioning wheel means, meansresponsive to pivoting movement of said arm in said opposite rotarydirection relative to said auxiliary frame to move said control means tosaid second position during final operation of the seal formingmechanism, and means responsive to movement of said actuating arm andsaid auxiliary frame in said first rotary direction through and beyondsaid first arcuate region for releasing strap tension and for resettingsaid drive pawl to ratcheting relation and returning said control meansto said first position.

6. In a strapping tool for tensioning and sealing the overlapping endsof a strap loop that encircles an object, a main frame having meansproviding a fixed pivot axis and means mounting a floating axis parallelto and swingable about the pivot axis, tensioning wheel means rotatableabout the floating axis, an auxiliary frame swingable about saidfloating axis, a drive pawl carried by said auxiliary frame and havingratcheting engagement with said tensioning wheel means during swingingmovement of said auxiliary frame about the floating axis in a firstrotary direction through a first arcuate range of swinging movement, asealer head mounted on said auxiliary frame for movement to and fromsealing position, an actuating arm swingable conjointly with saidauxiliary frame and sealer head for ratcheting said wheel means in saidfirst rotary direction, said arm being pivotable relative to saidauxiliary frame when the sealer head is at sealing position to move inan opposite rotary direction for operating said sealer head to crimp aseal about said overlapping ends, a pawl control element shiftablycarried in said auxiliary frame to move between a first position whereinthe drive pawl is held in ratcheting engagement with the tensioningwheel means and a second position wherein the drive pawl is free of thetensioning wheel means, means resiliently maintaining the pawl controlelement in said first position, means responsive to pivoting movement ofsaid arm in said opposite rotary direction relative to said auxiliaryframe to move said pawl control element to said second position duringfinal operation of the seal forming mechanism, and cam means projectingfrom said drive pawl and responsive to movement of said actuating armand said auxiliary frame in said first rotary direction and through andbeyond said first arcuate region for engaging an abutment on said mainframe for reset of said drive pawl and return of said pawl controlelement to said first position.

7. In a strapping tool for tensioning and sealing the overlapping endsof a strap loop that encircles an object, a main frame having meansproviding a fixed pivot axis and means mounting a floating axis parallelto and swingable about the pivot axis, tensioning wheel means rotatableabout the floating axis, an auxiliary frame swingable about saidfloating axis, a drive pawl carried by said auxiliary frame and havingratcheting engagement with said tensioning wheel means during swingingmovement of said auxiliary frame about the floating axis in a firstrotary direction through a first arcuate range of swinging movement,said drive pawl being rotatably shiftable in said auxiliary framebetween a normal position of ratcheting engagement with said tensioningwheel means and a second position free of such engagement, said pawlhaving an end extension cam and said main frame having a cooperatingabutment to engage said cam and offset rotation of said pawl from saidsecond position to said normal position in response to swinging movementof the auxiliary frame in said first rotary direction to move throughand beyond said first rotary direction, a sealer head mounted on saidauxiliary frame for movement to and from sealing position, an actuatingarm swingable conjointly with said auxiliary frame and sealer head forratcheting said wheel means in said first rotary direction, said armbeing pivotable relative to said auxiliary frame when the sealer head isat sealing position to move in an opposite rotary direction foroperating said sealer head to crimp a seal about said overlapping ends,a pawl control element slidably carried in said auxiliary frame to m vbetween first and second stable positions, said pawl control elementhaving interlocking engagement with said drive pawl when acting to holdsaid drive pawl in normal position and said pawl control element havinga sidewise directed detent socket, a detent pin mounted in saidauxiliary frame and having a conical point enterable into such socket tohold said control element in its first stable position wherein saidcontrol element holds said pawl in normal position, resilient meansmounted in said auxiliary frame and yieldably biasing said detent pinagainst said control element, and means incorporated in said sealforming mechanism and responsive during operation thereof while at thejoint forming position for engaging and shifting the pawl controlelement from said first to said second stable position with said detentpin yieldably retracting from the detent socket to accommodate suchmovement of the pawl control element.

8. In a binding tool of the type having a main frame that is engageablewith an object to be bound and that receives overlapping ends of a loopof strap encircling the object, rotary strap tensioning wheel meansswingably mounted about a pivot axis through said main frame androtatable about a floating wheel axis intermediate of said pivot axisand said main frame, an auxiliary frame carrying seal forming mechanismand swingably mounted about said wheel axis to move to and from jointforming position, a drive pawl carried by said auxiliary frame andhaving ratcheting engagement with said tensioning wheel means duringswinging movement of said auxiliary frame in a first rotary directionand an actuating arm swingable about said pivot axis conjointly withsaid auxiliary frame during the first arcuate region of swingingmovement for ratcheting said wheel means in said first rotary direction,said arm being pivotable relative to said auxiliary frame when the sealforming mechanism is at joint forming position to move relative theretoin an opposite rotary direction for operating said seal formingmechanism to crimp a seal about said overlapping ends, the improvementcomprising control means carried by said auxiliary frame and shiftablebetween first and second stable positions, said control means when insaid first stable position acting to hold the drive pawl in ratchetingengagement with the tensioning wheel means and when in said secondstable position allowing the drive pawl to be free of ratchetingengagement with the tensioning wheel means, means responsive to pivotingmovement of said arm in said opposite rotary direction relative to saidauxiliary frame to move said control means to said second positionduring final operation of the seal forming mechanism, and meansresponsive to movement of said actuating arm and said auxiliary frame insaid first rotary direction through and beyond said first arcuate regionfor releasing strap tension and for resetting said drive pawl toratcheting relation and returning said control means to said firstposition.

9. In a binding tool of the type having a main frame that is engageablewith an object to be bound and that receives overlapping ends of a loopof strap encircling the object, rotary strap tensioning wheel meansswingably mounted about a pivot axis through said main frame androtatable about a floating wheel axis intermediate of said pivot axisand said main frame, an auxiliary frame carrying seal forming mechanismand swingably mounted about said wheel axis to move to and from jointforming position, a drive pawl carried by said auxiliary frame andhaving ratcheting engagement with said tensioning wheel means duringswinging movement of said auxiliary frame in a first rotary directionand an actuating arm swingable about said pivot axis conjointly withsaid auxiliary frame during a first arcuate region of swinging movementfor ratcheting said wheel means in said first rotary direction, said armbeing pivotable on said auxiliary frame when the seal forming mechanismis at joint forming position to move relative thereto in an oppositerotary direction for operating said seal forming mechanism to crimp aseal about said overlapping ends, the improvement comprising a pawlcontrol element shiftably carried in said auxiliary frame to movebetween a first position wherein the drive pawl is held in ratchetingengagement with the tensioning wheel means and a second position whereinthe drive pawl is free of the tensioning wheel means, means resilientlymaintaining the pawl control element in said first position, meansresponsive to pivoting movement of said arm in said opposite rotarydirection relative to said auxiliary frame to move said pawl controlelement to said second position durng final operation of the sealforming mechanism, and means responsive to movement of said actuatingarm and said auxiliary frame in said first rotary direction and throughand beyond said first arcuate region for releasing tension and forreturning the pawl control element to said first position and resettingsaid drive pawl. I10- In a binding tool of the type having a main framethat is engageable with an object to be bound and that receivesoverlapping ends of a loop of strap encircling the object, rotary straptensioning wheel means swingably mounted about a pivot axis through saidmain frame and rotatable about a floating wheel axis intermediate ofsaid pivot axis and said main frame, an auxiliary frame carrying sealforming mechanism and swingably mounted about said wheel axis to move toand from joint forming position, a drive pawl carried by said auxiliaryframe and having ratcheting engagement with said tensioning wheel meansduring swinging movement of said auxiliary frame in a first rotarydirection and an actuating arm swingable about said pivot axisconjointly with said auxiliary frame during a first arcuate region ofswinging movement for ratcheting said Wheel means in said first rotarydirection, said arm being pivotable on said auxiliary frame when theseal forming mechanism is at joint forming position to move relativethereto in an opposite rotary direction for operating said seal formingmechanism to crimp a seal about said overlapping ends, the improvementcomprising a pawl control element shiftably carried in said auxiliaryframe to move between a first position wherein the drive pawl is held inratcheting engagement with the tensioning wheel means and a secondposition wherein the drive pawl is free of the tensioning wheel means,means resiliently maintaining the pawl control element in said firstposition, means responsive to pivoting movement of said arm in saidopposite rotary direction relative to said auxiliary frame to move saidpawl control element to said second position during final operation ofthe seal forming mechanism, and cam means projecting from said drivepawl and responsive to movement of said actuating arm and said auxiliaryframe in said first rotary direction and through and beyond said firstarcuate region for engaging an abutment on said main frame for reset ofsaid drive pawl and of said pawl control element to said first position.

11. In a binding tool of the type having a main frame that is engageablewith an object to be bound and that receives overlapping ends of a loopof strap encircling the object, rotary strap tensioning wheel meansswingably mounted about a pivot axis through said main frame androtatable about a floating wheel axis intermediate of said pivot axisand said main frame, an auxiliary frame carrying seal forming mechanismand swingably mounted about said wheel axis to move to and from jointforming position, a drive pawl carried by said auxiliary frame andhaving ratcheting engagement with said tensioning wheel means duringswinging movement of said auxiliary frame in a first rotary directionand an actuating arm swingable about said pivot axis conjointly withsaid auxiliary frame during a first arcuate region of swinging movementfor ratcheting said wheel means in said first rotary direction, said armbeing pivotable relative to said auxiliary frame when the seal formingmechanism is at joint forming position to move relative thereto in anopposite rotary direction for operating said seal forming mechanism tocrimp a seal about said overlapping ends, the improvement wherein saiddrive pawl is rotatably shiftable in said auxiliary frame between anormal position of ratcheting engagement with said tensioning wheelmeans and a second position free of such engagement, said pawl having anend extension cam and said main frame having a cooperating abutment toengage said cam and elfect rotation of said pawl from said secondposition to said normal position in response to swinging movement of theauxiliary frame in said first rotary direction to move through andbeyond said first arcuate region, a pawl control element slidablycarried in said auxiliary frame to move between first and second stablepositions, said pawl control element having interlocking engagement withsaid drive pawl when acting to hold said drive pawl in normal positionand said pawl control element having a sidewise directed detent socket,a detent pin mounted in said auxiliary frame and having a conical pointenterable into said socket to hold said control element in its firststable position wherein said control element holds said pawl in normalposition, resilient means mounted in said auxiliary frame and yieldablybiasing said detent pin against said control element, and meansincorporated in said seal forming mechanism and responsive duringoperation thereof while at the joint forming position for engaging andshifting the pawl control element from said first to said second stableposition with said detent pin yieldably retracting from the detentsocket to accommodate such movement of the pawl control element.

12. The combination in a hand held portable strapping tool comprising amain frame having a handle arched above a base that is adapted to engageagainst an object to be tied by a strap loop having overlapping lead andsupply ends, said handle terminating in laterally flaring wall structurethat merges at one extremity with upstanding side wall structure of saidbase and cooperatively therewith provides opposed regions that flank anddefine a central pocket, said main frame having means providing a fixedpivot axis extending between said opposed regions and means mounting afloating axis parallel to and swingable about the pivot axis, tensioningwheel means mounted to rotate about the floating axis, an auxiliaryframe swingable about the floating axis, said auxiliary frame carrying aseal head assembly that includes casing structure rigid with theauxiliary frame and housing seal forming mechanism, seal storagemechanism and seal feeding mechanism, a drive pawl carried by saidauxiliary frame and having ratcheting engagement with said tensioningwheel means during swinging movement of said auxiliary frame about thefloating axis in a first rotary direction through a first arcuate rangeof swinging movement, spring means reacting between the main frame andthe tensioning wheel means normally to maintain the floating axis at alocation that is maintained during the said first arcuate range ofswinging movement, an actuating arm pivotable about an axis through saidcasing structure but movable conjointly with the auxiliary frame forratcheting said wheel means in said first rotary direction, said armbeing pivotable about said casing axis when the seal forming mechanismis at sealing position to move in an opposite rotary direction foroperating said seal forming mechanism to crimp a seal about saidoverlapping ends, means responsive to operation of the sealer head'fordisengaging the drive pawl to avoid further strap tensioning followingcrimping of the seal, and means responsive upon swinging said actuatingarm and auxiliary frame through and beyond said first arcuate range ofmovement for elevating the wheel means against the action of said springmeans for setting the drive pawl to a position of ratcheting engagement.

13. The combination in a hand held portable strapping tool comprising amain frame having a handle arched above a base that is adapted to engageagainst an object to be tied by a strap loop having overlapping lead andsupply ends, said handle terminating in laterally flaring wall structurethat merges at one extremity with upstanding side wall structure of saidbase and cooperatively therewith provides opposed regions that flank anddefine a central pocket, said main frame having means providing a fixedpivot axis extending between said opposed regions and means mounting afloating axis parallel to and swingable about the pivot axis, tensioningwheel means mounted to rotate about the floating axis, an

Cit

auxiliary frame swingable about the floating axis, said auxiliary framecarrying a seal head assembly that includes casing structure rigid withthe auxiliary frame and housing seal forming mechanism, seal storagemechanism and seal feeding mechanism, a drive pawl carried by saidauxiliary frame and having ratcheting engagement with said tensioningwheel means during swinging movement of said auxiliary frame about thefloating axis in a first rotary direction through a first arcuate rangeof swinging movement, spring means reacting between the main frame andthe tensioning wheel means normally to maintain the floating axis at alocation that is maintained during the said first arcuate range ofswinging movement, an actuating arm pivotable about an axis through saidcasing structure but movable conjointly with the auxiliary frame forratcheting said wheel means in said first rotary direction, said armbeing pivotable about said casing axis when the seal forming mechanismis at sealing position to move in an opposite rotary direction foroperating said seal forming mechanism to crimp a seal about saidoverlapping ends, a pawl control element shiftably carried in saidauxiliary frame to move between a first position wherein the drive pawlis held in ratcheting engagement with the tensioning wheel means and asecond position wherein the drive pawl is free of the tensioning wheelmeans, means resiliently maintaining the pawl control element in saidfirst position, means responsive to pivoting movement of said arm insaid opposite rotary direction relative to said auxiliary frame to movesaid pawl control element to said second position during final operationof the seal forming mechanism, and means responsive to movement of saidactuating arm and said auxiliary frame in said first rotary directionand through and beyond said first arcuate region for releasing tensionand for returning said pawl control element to said first position andresetting said drive pawl.

14. An arrangement in accordance with claim 13 and wherein a holdingpawl is rotatable upon the pivot axis for the tensioning wheel means andis resiliently biased to holding engagement therewith and a releaseelement is carried on the auxiliary frame to engage the holding pawlwhen the actuating arm is swung to adjacent the handle and lifts thetensioning wheel means against the action of said spring means.

15. In a strapping tool for tensioning the overlapping ends of a straploop encircling an object comprising a frame, a tensioning wheel mountedon the frame for movement toward and away from a strap gripping stationon the frame, said strap gripping station being provided with a strapgripper which is adjustably mounted for positioning the strap gripper atdifferent strap gripping levels at said strap gripping station, a spacermember movable conjointly with said tensioning wheel and projecting in aradial direction beyond the wheel and in the path of the strap gripperat any position to which it can be adjusted, whereby movement of-thetensioning wheel to the strap gripping station allows contact of theprojecting part of said spacer member with the strap gripper to therebymaintain a minimum spacing between the tensioning wheel and the strapgripper corresponding to the amount the spacer member projects beyondthe wheel.

16. In a strapping tool for tensioning the overlapping strap ends of astrap loop encircled about an object comprising a frame, a strapgripping station on the frame over which the strap ends are extendedwhen tensioning, a strap gripper mounted in the frame at said stationand adjustable to different levels, a tensioning wheel mounted on theframe for movement toward and away from said station and provided with aspacer member movable conjointly with the tensioning wheel, said spacermember projecting radially beyond the tensioning wheel and in the pathof the strap gripper at any position to which it is adjusted, wherebythe spacer member contacts said strap gripper when the tensioning wheelis moved to said station, the amount the spacer member projects beyond17 the tensioning wheel determining the spacing between the tensioninwheel and the spacer member.

17. In a strapping tool as defined by claim 16 comprising said strapgripper being circular in cross-section and provided with an annularsurface which provides said contact with said spacer member through afull 360 positioning of said strap gripper.

18. In a strapping tool as defined by claim 16 comprising said strapgripper being threadably secured to said frame to provide its adjustmentto said different levels by rotating it, an annular surface beingprovided on the strap gripper in alignment with the spacer member toprovide a full 360 region of contact between the strap gripper and thespacer member.

References Cited UNITED STATES PATENTS 1/ 1937 Waldorf 140-93.4 12/ 1937Spencer 14093.4 12/ 1943 Leslie 14093.4

2/1950 Leslie 14093.4 12/1953 Crosby et a1. l40--93.4

5/1962 Hall et a1 14093.4

10 CHARLES w. LANHAM, Primary Examiner.

E. M. COMBS, Assistant Examiner.

